Replacing house batteries

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rhumbline2
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Re: Replacing house batteries

Postby rhumbline2 » Wed Nov 09, 2016 5:03 pm

Yes, I ran the large wires from the breaker. I'm no electrician, but I do know that larger wires for long runs is better. I used extra large wires. Like most projects involving boats, it was a chore, however, I found the difference it made to be considerable. Hope this helps.

James Mills
Hull #27
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deising
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Re: Replacing house batteries

Postby deising » Wed Sep 26, 2018 4:18 am

In Sep 2016, Mac Carter wrote that he was replacing the house batteries with AGMs with a goal of being able to go three days at anchor before having to recharge.

Having cruised approximately 500 days/nights on our PDQ in less than 4 years, I find that our 4 Trojan T-145 flooded wet cell batteries generally do fine overnight after shutting down with a 95% to full charge early afternoon. Adding the 360W solar panel array above the aft Bimini in summer of 2017 helped that even more, but it would be the rare day that we could sit at anchor without running the generator for 45 minutes in the morning.

So, we would never consider going more than 1 day without running the generator or running the boat to a new destination for 3-4 hours for an alternator recharge. Therefore, my question - Mac, how is your new setup working out compared to your goals and expectations?
Duane Ising
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade

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AMCarter3
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Re: Replacing house batteries

Postby AMCarter3 » Sat Nov 17, 2018 11:58 am

Duane asked me (privately) how my battery replacement project played out vs. my objectives... Here's what I sent to him. I tried to send this reply to the forum last week, but it did not go through. Apparently there have been some tech problems that have impacted our ability to reply on this forum. Sam tells me the issue is fixed now.

'Replacing our wetcells with 4 220-amp AGM’s has been a great improvement overall. We now get 2-3 days at anchor (conservative power use) and can charge the AGM's to about 90% in 3-4 hours of running.

However, the 1st smart charger and high capacity alternator were a bust. The alternator literally melted down last winter. It was hard to diagnose. I'm pretty sure it was defective. I also discovered the smart charger had not been wired to detect high temp at the alternator. It was such a bad experience trying to get help from the alternator (Electromaxx) and Charger (Sterling) manufacturers, I decided to scrap both and start that part over last Spring. I installed a more expensive 165 amp Balmar "AT" alternator (their latest technology) and regulator. Balmar is highly respected in the West Coast boating community and their tech support is terrific. Another example of "you get what you pay for!".

There have been two unanticipated challenges in this has project. First, the weight of the big AGM batteries caused the stern to sink considerably. I have experimented several times with adding chain ballast to both bow chambers. That has worked pretty well to flatten the boat. However, the boat is still a bit stern heavy right now, but I have not seen any negative impact on boat speed.

The 2nd challenge has been figuring out how to reduce the high temp in the front of the port engine enclosure due to the high capacity alternator. We tracked the temperature for several weeks of operations and found it spiked to 130-140 degrees when the engine is run for several hours. That kind of high temp will age an alternator prematurely. There is hardly any air flow in that area. So, with help of a boating friend, I recently added a hi capacity Delta T Systems exhaust blower (replacing the cheap, noisey original blower) to the aft fire wall of that enclosure. We have setup so it turns on when the engine starts and runs on for 30 mins after the engine has shut done. We still need to do more temp data logging to verify it is helping reduce the temp in the port engine compartment.

So, net, we feel it has been an expensive, but very worthwhile upgrade. Lastly, we are also looking seriously at adding 2 solar panels this winter.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98; twin 100 HP Yanmar diesels
Bellingham WA (in charter with San Juan Sailing & Yachting)


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